Resealable container lid and method

ABSTRACT

A container construction is provided and includes a lid and receptacle. The lid is attachable to the receptacle in an area between lips extending from outer perimeters of the lid and receptacle using a bonding element that is permanently attached to one of the lips and heat sealed to the other of the lips. The lid includes a plug that fits within a mouth allowing resealing of the receptacle. Only one lid element is required to seal the receptacle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority on previously filed provisionalapplication U.S. Ser. No. 60/595,716, filed Jul. 29, 2005.

BACKGROUND OF THE INVENTION

Containers are commonly used for packaging items and in particular fooditems. Many types and forms of containers have been used each providingadvantages and disadvantages, usually simultaneously. A common type offood package involves a container bottom or receptacle forming a storagechamber with an opening. A lip or flange extends outwardly from theopening and provides a surface for securing a membrane type closure tocover, close and seal the opening. Typically, the membrane is a laminatehaving a metallic foil layer and a polymeric layer. The membrane issecured to the receptacle, as for example, by forming an adhesive bondor a seal through induction bonding. One problem with such membraneclosures is that during the opening process, they often delaminate eventhough they are not intended to, leaving residue of the membrane on thereceptacle or often tear requiring multiple steps to remove the membraneand fully open the container. Additionally, the container cannot beresealed using the removed membrane.

To solve the resealing problem, an overcap or lid was provided whichgenerally includes a generally planar wall member with a depending skirtwith a portion of the depending skirt and a portion of the peripherallip interengaging in some manner to retain the lid on the container.Such a multiple closure container though requires additional equipmenton the processing line and hence processing time to complete a filledand sealed container. The time to fill and seal the container, hereinreferred to as packaging time, can take up to two seconds adverselyaffecting line efficiency. Additionally, a multiple component closuresystem adds costs to the final product and in particular to thecontainer where margins tend to be low.

Thus, there is a need for an improved lid and combination lid andreceptacle and method of filling and container operation.

SUMMARY OF THE INVENTION

The present invention provides a lid and container constructionutilizing a lid and receptacle wherein the lid provides both peelableremoval and mechanical resealability. The construction permits theassembly and sealing of the container using existing online equipmentthat can effect the joining of the lid and receptacle in a quick andefficient manner.

A method of manufacturing the container is provided wherein a lid andreceptacle are formed and at least one is provided with a bondingelement that is permanently adhered to a lip and can be semi-permanentlyattached to another lip, as by heating, to effect fusion of the bondingelement. The bonding element, when it is desired to remove the lid,breaks while still remaining at least substantially permanently attachedat its original area of permanent attachment to a lip. The lid may thenbe moved exposing the contents of the container. The lid includes a plugthat can be inserted into the mouth of the receptacle and by use ofcooperatively interengageable elements, the lid is removably mounted tothe receptacle for resealing the receptacle. Optionally, the lid may beonly partially separated from the receptacle for exposing the contents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a container comprising the presentinvention.

FIG. 2 is an exploded perspective view of the container illustrated inFIG. 1.

FIG. 3 is a sectional view of the container taken along line 3-3 FIG. 1.

FIG. 4 is an enlarged fragmentary sectional view of a portion of thecontainer shown in FIG. 3.

Like numbers throughout the various Figures designate like or similarparts.

DETAILED DESCRIPTION

The reference 1 designates generally a container including a containerbottom or receptacle 3 and lid 4. The receptacle 3 has a sidewall 6,bottom wall 7 and a product access opening 8. The sidewall 6 and thebottom wall 7 define a storage chamber 10. The lid 4 is secured to thereceptacle 3 in an area 5 between overlapping lips or flanges 12, 13respectively. Securement of the lid 4 to the receptacle 3 can beeffected by a bonding element 15, FIG. 4. The bonding element 15 is partof one of the lips 12, 13 and overlies at least a portion of the otherof the lips 12, 13.

The receptacle 3 is in the form of an upwardly opening cup having amouth portion 18 adjacent the opening 8 and top 9. The mouth portion 18is at least partially defined by the sidewall 6 and terminates in thechamber 10 at a shoulder 19. As shown, the mouth 18 is generallycylindrical. The sidewall 6 may be any suitable shape or size and ispreferably generally circular in transverse cross section and may be inthe form of a straight wall or a tapered wall. If the sidewall 6 istapered, it is usually frusto-conically shaped and if straight walled,it may be generally cylindrical. Both shapes of sidewalls are shown inFIG. 3 with the straight sidewall being shown in phantom. A taperedsidewall can be shaped to provide for nesting of receptacles 3.Preferably, the bottom wall 7 has at least a substantial portion that isgenerally planar. The receptacle 3, if polymeric, can be suitably moldedsuch as thermoformed, vacuum formed or injection molded from suitablematerials as is known in the art. The receptacle 3 may also be formed ofother suitable materials for example, polymeric coated paperboard or thelike. The construction and material for the receptacle 3 will usually bedetermined by the product to be stored therein, processing conditions ofthe contents, e.g., retorting, and cost. The product 20, FIG. 3, may beany suitable product and in a preferred embodiment, the container 1 isparticularly useful with food products particularly those with a highliquid or semi-liquid content, such as water and/or lipids, for example,yogurt, pudding, fruit, dairy products, high fat (lipid) items such asmargarine, butter or the like. The materials forming the receptacle 3and lid 4 would be impermeable to the product 20 or components of theproduct 20. The material comprising the receptacle 3 may be a singlelayer of material, a multiply layer of material, a coated material or ablend of materials, as for example, a mixture of polymers. Suitablepolymers can include polyethylene (low or high density), polypropylene,polystyrene and the like and mixtures or laminates thereof. The materialmay need to meet regulatory requirements such as FDA requirements.Suitable colorants such as dyes or pigments may be incorporated orapplied and the exterior surface 21 may have printing and/or graphicsapplied thereto either by direct printing or by providing an add onlabel. Receptacles 3 of the general type or form as described above arewell known in the art as are their methods of manufacture and also thematerials used to comprise the same. The lip 13 has a generally upwardlyfacing surface 23 while the lip 12 has a generally downwardly facingsurface 24. The lip 13 extends generally radially outwardly of andperipherally (or circumferentially) about the sidewall 6 and hence thereceptacle 3 and the lip 12 extends generally radially outwardly of andperipherally (or circumferentially) about the lid 4. The mouth portion18 is adjacent the lip 13 and includes the opening 8. One of the lips12, 13 may be provided with a peripherally (or circumferentially)extending rib 25 for assisting in fastening the lid 4 and receptacle 3together particularly when joining the two together by sonic welding. Asshown, the rib 25 projects from the surface 23 and is an integral partof the lip 13 and has a distal or free edge 25E to (later described)contact the lip 12.

The lid 4 comprises the lip 12 extending outwardly from a plug portion27. The plug portion 27 includes a bottom wall 28 which is integral withand extends across the bottom end 29 of a sidewall 30 preferably formingan upwardly opening recessed pocket 31. The wall 28 is positionedadjacent the shoulder 19 and may rest thereupon. The sidewall 30connects the lip 12 to the wall 28. The transverse shape of the sidewall30 is similar to the shape and size of the mouth 18 and is receivabletherein. The receptacle 3 and lid 4 have cooperatively interengageableelements usable to help releasably secure at least a portion the lid 4to the receptacle 3 after the container 1 is opened to effect resealingof the chamber 10. In the illustrated structure, the cooperativelyinterengageable elements includes a pair of peripherally (orcircumferentially) extending ribs 32, 33 with the rib 32 being a portionof the sidewall 30 and projecting radially outwardly therefrom and therib 33 being a portion of sidewall 6 and projecting radially inwardlytherefrom. The rib 33 is positioned at an elevation higher than the rib32 when the lid 4 is attached to the receptacle 3 providing aninterference fit and a snap lock connection between the lid 4 andreceptacle 3. The rib 32 and lip 12 form a recess therebetween. The ribs32, 33 may be substituted with frictional engagement between thesidewall 30 and the sidewall 6 or one of the sidewall 6 and sidewall 30may be provided with a groove and the other of the sidewalls 6 and 30 beprovided with a rib to provide the cooperatively interengageableelements.

As seen in FIGS. 1, 2 and 3, the lid 4 may be provided with a hingedevice 35 which allows flexing of one lid portion 36 relative to a lidportion 37. In the illustrated structure, the sidewall 30 hasinterruptions or discontinuities 39 forming notches in the sidewall 30at opposite ends of a groove or channel 40. The groove 40 is defined bya pair of walls 41, 42 joined together at an apex 43 and to the wall 28as at 44, 45 (FIG. 3). The apex 43 is at a level or height adjacent tothe lip 12. By providing the interruptions 39 in the sidewall 30, theportion 36 may hinge about the apex 43 and relative to the lid portion37. A living hinge is thus provided between walls 41, 42 and between lidportions 36, 37. Further details of the operation and construction ofthe container are provided below.

The bonding element 15 is positioned between portions of the lips 12, 13and is permanently attached to one of the lips 12, 13 to become part ofthe lip and is attached to the other of the lips. The bonding element 15is best seen in FIG. 4. In a preferred embodiment, the lid 4 is alaminate structure having a first laminate ply or layer 44 and a secondlaminate ply or layer 45. Preferably, both plies 44, 45 at leastsubstantially completely cover their respective side of the lid 4. Theformation of such a laminate structure is well known in the art and canbe made such as by co-molding, e.g., co-extrusion. The ply 45 isadjacent to the receptacle 3. The ply 45 has a portion thereof formingthe bonding element 15 and is readily heat sealable to a portion of thesurface 23 and hence the lip 13 at peripherally (or circumferentially)extending rib 25 at its free edge 25E. As shown, the rib 25 and lips 12,13 are annular. The details of the bonding area are enlarged and not toscale in FIG. 4 to better show detail. The heat sealing temperature andthus the melting point of the ply 45 and bonding member 15 is preferablyin the range between about 120° C. (248° F.) and about 145° C. (293° F.)and the material of the lip 13 and its rib 25 is fusible with thebonding element 15. This temperature range is particularly useful whenthe receptacle 3 is made out of polypropylene. It is to be understoodthat the bonding element 15 may be a portion of the receptacle 3 and,may be a ply similar to the ply 45 wherein the receptacle 3 could alsobe a laminate structure. It is also to be understood, that the bondingelement 15 can be applied in a selected area and made part of on one orthe other of the lips 12, 13 and not cover the entirety of either thereceptacle 3 or lid 4. Optionally, the rib 25 may be eliminated but hasbeen found to be beneficial when the heat bonding of the lid 4 to thereceptacle 3 is by sonic welding. The bonding element 15 has a breakstrength, which may be a combination of both tensile and shear, as morefully discussed below, less than the strength of the permanentattachment of the bonding element as at 47 to the ply 44. Thus, when thelid 4 is removed from the receptacle 3, the bonding element 15 breaksbut stays joined to at least a substantial portion and preferablycompletely attached to lip 12 at its area of permanent bonding to ply44. The break may also occur partially or completely at the heat bond 5between the rib 25 and bonding element 15 to separate the twocomponents. The bond 5 formed between the lid 4 and receptacle 3 can becharacterized by an absence of cut or score lines used in the prior artto assist in separating the lid 4 from the receptacle 3. It may beuseful to provide un-joined margins between at least of portion of thelips 12, 13 particularly at a pull tab 48. As seen, in FIG. 4, the bond5 does not extend to the outer edges and inner edges of the lips 12, 13providing gaps or un-joined margins between the outer and inner edgeportions of the lips 12, 13.

In a preferred embodiment, at least the lip 12 is resilientlydeformable, i.e., can be bent at least about 90° and return under itsown resilience or elastic deformability substantially to its originalposition. Preferably all components of the lid 4 and receptacle 3 areresiliently deformable and in particular, the lips 12, 13.

The pull tab 48 preferably is an integral part of the lip 12 and isformed when the lid 4 is formed as for example by die cutting. The tab48 provides a gripping element for use by a consumer to effect openingof the container 1. To open the container 1, the user will typicallybend the tab 48 upwardly and then into a reverse bend to start afracture (see FIG. 3 where the bent tab 48 is shown in phantom) in thebonding element 15 and then by pulling the tab 48 across the opening 8of the container will break the bonding element 15 without substantialand preferably no delamination between the plies 44, 45. Preferably, thebonding element 15 breaks within itself and /or the bond 5 formedbetween the bonding element 15 and the rib 49 of the lip 13. Byutilizing the above described construction, the membrane that istypically used on such containers can be eliminated. Preferably the lip13 is more resistant to bending during opening than the lip 12. This canbe accomplished by a combination of material properties and relativethicknesses of the lips.

To manufacture a container 1, a receptacle 3 is suitably formed as forexample by thermoforming, vacuum forming or injection molding. In theillustrated structure, wherein the lid 4 is multi-plied, a laminate isfirst formed which can then be suitably formed into a lid 4 for exampleby thermoforming or vacuum forming. The outer edge of the lid 4 can bedie cut depending upon the forming method of the lid 4. Likewise, and incertain molding methods, the outer edge of the receptacle 3 may also bedie cut. Typically, such containers are formed offsite from the fillingplant. Thus, the lids 4 and receptacle 3 would be packaged and forwardedto a processing plant. The receptacles 3 and lids 4 are transferred to aprocessing line and the receptacles 3 are positioned in an upwardlyopening direction. As described herein, the positional references to thecontainer construction are those when the container is in its normallyupwardly opening condition and the lid is in its normal position forattachment to or attached to the receptacle 3. The receptacle 3 isconveyed through a filling line which has a depositor which will deposita predetermined amount of product 20 into the chamber 10. It ispreferred to prevent product from dripping or trailing onto the lip 13which might interfere with heat bonding. The thus filled receptacle 3 istransferred to a lid depositing station where a lid 4 is deposited onthe receptacle 3. The plug portion 27 is inserted into the mouth 18wherein the lips 12, 13 are in overlapping orientation. Additionally,the cooperatively interengaging elements, for example the ribs 32, 33are positioned relative to one another to hold the lid 4 in place duringits transfer to a sealing station. A heat seal device 55, including aheated element 55A and a support 55B, which are shown in phantom in FIG.4, will then apply heat and pressure to the lip 12 to effect a heat sealbond of the bonding element 15 to one of the lips 12, 13. Heat may beapplied in my suitable manner, e.g., conduction, radiation convection(e.g., hot air) or may be generated at the bonding area (e.g., sonicwelding). In the illustrated construction, the bonding element 15 isheat bonded to the lip 13 at the bond area 5 which is illustrated as anannular area extending around the entirety of the lips 12, 13.Optionally, the sealing force applied and the heat for bonding may beprovided separately and by separate devices if desired. The appliedbonding force and hence pressure is adequate to reach a so called hardstop, i.e., enough to effect good bonding but preferably not enough toforce excessive flow of heated bonding element 15 or adjacent material.One or more gaps 57A, 57B may be provided on one or both of oppositesides of rib 49 between the lips 12, 13 that are not bonded which gapsextends inwardly and outwardly from the rib 49 and preferably at leastsubstantially completely around the perimeters of the lips 12, 13. Thegaps 57A or 57B may also be provided on opposite sides of the bond area5 if a rib 49 is not utilized. The gap 57A extends inwardly from theouter perimeter of the lips 12, 13 a distance of at least about 0.03inches at least adjacent the tab 48 and preferably at least about 0.06inches. The rib 49 has a free end 49E engageable with the lip 12 thathas downwardly inclined portions, for example, the end 49E may betransversely radiused. The rib 49 and gaps 57A, B are useful when sonicwelding are used to effect heat bonding. However, in another embodiment,the gap can be only in the vicinity of the pull tab 48. In still anotherembodiment, no gaps 57A, B are formed when other than sonic welding issued to effect heat bonding. By pulling the tab 48 across the top of thereceptacle 3, the bonding element 15 breaks and does not substantiallyseparate from the lip to which it is permanently adhered which in theillustrated structure is lip 12. The lip 12 and preferably the remainderof the lid 4 is relatively rigid and has a thickness in the range ofbetween about 0.008 and about 0.016 inches with a thickness of about0.012 inches having been found workable. It is preferred that the lip 13have a thickness in the range of between 0.025 and about 0.045 incheswith a thickness of about 0.035 inches being workable. Preferably thelip 13 is more rigid than the lip 12. The remainder of the receptacle 3has a thickness in the range of between about 0.01 and about 0.025inches with a thickness of about 0.015 inches having been foundworkable. The thickness described may vary across the particular partdepending on the method of part manufacture. For example, in vacuumforming, material is stretched resulting in thinned areas depending onthe amount and location of stretch. Membrane closures of the prior artof food containers have a thickness in the range of between 0.002 andabout 0.005 inches. The rib 5 has a height in the range of between about0.01 and about 0.03 inches with a height of about 0.02 inches havingbeen found workable. The filled container 1 with the lid 4 bonded to thereceptacle 3, after exiting the filling line, can be stored. Afterstorage and distribution, a consumer can easily open the container I(separating the lid 4 from receptacle 3 as by breaking the bondingelement 15 most conveniently by pulling the tab 48 across the opening 8.The separation of the lid 4 from the receptacle 3 does not need to becompletely around the perimeter of the opening 8 but the lid 4 can beleft attached in the area A (FIG. 1) on one side of the apex 43 allowingthe lid 4 to remain partially attached to the receptacle 3. Differentialbonding of the lid 4 to the receptacle 3 can be used between the lips12, 13 in the zones A, B to assist in facilitating opening and retainingthe lid partially attached. The lid portion in area B (FIG. 1) on theother side of the apex 43 can be bent at the apex 43 allowing access tothe chamber 10 and product 20 while still being partially attached tothe receptacle 3. The lid 4 can be completely separated from thereceptacle 3 as well. To reseal the container 1, the lid 4 is placedback into the mouth 18 whereby the cooperatively interengaging elements,for example the ribs 32, 33 releasably retain the lid 4 mounted to thereceptacle 3.

A typical filling line requires just a matter of seconds to fill andeffect attachment of a membrane lid and overcap lid to a containerbottom. There may be some time lag during the transfer of a filledreceptacle 3 to a capping station and to place a lid 4 into a receptacleprior to bonding. Bonding of a lid has taken about 2 seconds whilefilling takes less time. The use of the present invention has reducedthe 2 second package completion time to a time period on the order ofabout 0.5 seconds to 1.0 seconds to effect lid to receptacle bonding asby heat sealing with success being had at effecting lid bonding afterfilling in a time period of about 0.7 seconds or less. The presentinvention may be used on existing production lines with little or nomodifications to the lines.

Thus, there has been shown and described several embodiments of a novelinvention. As is evident from the foregoing description, certain aspectsof the present invention are not limited by the particular details ofthe examples illustrated herein, and it is therefore contemplated thatother modifications and applications, or equivalents thereof, will occurto those skilled in the art. The terms “having” and “including” andsimilar terms as used in the foregoing specification are used in thesense of “optional” or “may include” and not as “required”. Manychanges, modifications, variations and other uses and applications ofthe present construction will, however, become apparent to those skilledin the art after considering the specification and the accompanyingdrawings. All such changes, modifications, variations and other uses andapplications which do not depart from the spirit and scope of theinvention are deemed to be covered by the invention which is limitedonly by the claims which follow.

1. A method of making a container said method including: forming areceptacle with a product storage chamber and a mouth portion, thereceptacle also having a generally outwardly extending peripheral firstlop with a first surface; forming a lid having a generally outwardlyextending second lip with a second surface and having a plug portionsized and shaped to be received within the mouth portion; depositingproduct into the chamber in a first time period; mounting the lid to thereceptacle after the depositing, with said plug being positioned withinthe mouth portion and the first and second surfaces facing one another;and bonding a portion of the first lip to a portion of the second lip ina second time period and thereby sealing the product in the container,said first lip being severable from the second lip for opening the lid,the second time period being less than about 1 second.
 2. The method asset forth in claim 1 including forming a rib as part of one of the firstand second lips and having a free edge engageable with the other of thefirst and second lips.
 3. The method as set forth in claim 2 includingbonding the free edge of the rib to the other of the first and secondlips by heat sealing.
 4. The method as set forth in claim 3 includingforming a tab on the second lip.
 5. The method as set forth in claim 4including forming an unbonded area between the first and second lipsextending inwardly from an outer perimeter of the lips to the heat sealat least adjacent the tab.
 6. The method as set forth in claim 5including forming cooperatively interengageable elements on thereceptacle and lid in a mouth region of the receptacle.
 7. The method asset forth in claim 6 including forming the second lip with a bondingelement to engage the free edge of the rib for heat sealing thereto,said second time period being less than about 0.7 seconds.
 8. Aresealable container comprising: a receptacle defining a product storagechamber and having a sidewall portion with a free end portion definingan opening providing access to the chamber and having a generallyoutwardly extending peripheral first lip with a generally upwardlyfacing first surface, said sidewall having a mouth portion adjacent thefree end portion and first lip; a lid having a generally outwardlyextending peripheral second lip with a generally downwardly facingsecond surface overlying a portion of the first surface at least one ofthe first and second surfaces having a rib projecting therefrom andsecured to a portion of the other of the first and second surfaces, saidlid having a plug portion depending from the second lip and positionedin the mouth portion and having a hinge member extending across aportion of the plug portion and separating said lid into first andsecond lid portions with said first lid portion being selectivelymovable about a portion of the hinge member relative to the second lidportion, said lid being secured to the receptacle at the first andsecond lips.
 9. A resealable container as set forth in claim 8 at leastone of the first and second lips including a bonding element securingthe lid to the receptacle in an area between the first and second lipsat said bonding element said rib being bonded to at least one of saidreceptacle and lid.
 10. The resealable container as set forth in claim 9wherein said bonding element including a ply laminated to a lip portionof one of the lid and receptacle.
 11. The resealable container as setforth in claim 8 including a tab member associated with the second lip.12. The resealable container as set forth in claim 11 wherein at least aportion of the first and second lips each having an outer edge, at leasta portion of the first and second lips being unbonded in an areatherebetween and extending inwardly of the outer edges.
 13. Theresealable container as set forth in claim 12 wherein the unbonded areabeing at least adjacent said tab.
 14. The resealable container of claim13 including cooperatively interengagable elements associated with thelid and the receptacle to permit selectively maintaining the lid in aclosed condition after the lid has been moved to an open position. 15.The resealable container of claim 13 wherein the plug portion includinga sidewall with a discontinuity at each end of the hinge memberpermitting flexing of a living hinge portion of the hinge member. 16.The resealable container of claim 8 wherein the plug portion including asidewall with a discontinuity at each end of the hinge member permittingflexing of a living hinge portion of the hinge member.
 17. Theresealable container of claim 16 wherein the hinge member including apair of walls extending from a bottom wall of the plug portion andhaving the living hinge portion therebetween.
 18. The resealablecontainer of claim 17 wherein the pair of walls defining a groovetherebetween.
 19. The resealable container of claim 18 wherein thegroove opening into said chamber.
 20. The resealable container of claim8 including cooperatively interengagable elements associated with thelid and an upper portion of the receptacle to permit selectivelymaintaining the lid in a closed condition after the lid has been movedto an open position.
 21. The resealable container of claim 20 wherein atleast one of the interengagable elements including a rib.